Marketable Securities - Additional Information (Detail) - USD ($) $ in Millions	May 31, 2020	May 31, 2019
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale debt securities, current	$ 7.6	$ 8.6
Available-for-sale debt securities, long-term	19.3	16.4
Equity securities	$ 87.1	$ 87.5
Maximum
Schedule of Available-for-sale Securities [Line Items]
Investments with unrealized loss, percentage of fair values less than original cost	15.00%	15.00%
Trading Securities
Schedule of Available-for-sale Securities [Line Items]
Securities held in relation to deferred compensation plan	$ 9.1	$ 12.3

Percentage of carrying value over fair value.

No definition available.

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- Definition

Carrying amount as of the balance sheet date of assets held under deferred compensation agreements.

+ References

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Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount of investment in marketable security, classified as current.

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Amount of investment in marketable security, classified as noncurrent.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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